Textile dyeing industry: environmental impacts and remediation

Using textile industrial sludge, sewage wastewater, and sewage sludge as inoculum to degrade recalcitrant textile dyes in a co-composting process: an assessment of biodegradation efficiency and compost phytotoxicity

Recalcitrant dyes found in textile wastewater represent a threat for sustainable textile production due to their resistance to conventional treatments. This study assessed an alternative co-composting system for the treatment of recalcitrant textile dyes where textile industrial sludge, sewage wastewater, or sewage sludge were used as microbial compost inocula. The biodegradation efficiency of bioreactor trials and compost quality of the co-composting system were assessed by visible spectrophotometry and by a phytotoxicity test. The co-composting system (dry weight (dw) basis) consisted of 200 g of restaurant organic residues + 200 g sewage sludge (or 100 mL sewage wastewater, or 200 g textile sludge) + 100 mL of a 10% dye solution (Reactive Red 195, or Synolon Brown, or Orange Remazol, or Yellow Synozol, or Reactive Orange 122, or Reactive Black 5). After 60 days of composting, all dyes were biodegraded according to spectrophotometric data, with efficiency varying from 97.2 to 99.9%. Inoculum efficiency ranking was textile sludge > sewage sludge > sewage wastewater. Regarding compost quality, a phytotoxicity study with lettuce showed no toxicity effect. Thus, co-composting can be a low-cost and efficient method for recalcitrant textile dye biodegradation and for managing textile sludge in terms of waste recycling, contributing to environmental sustainability.

Environmental friendly extraction of walnut bark-based juglone natural colorant for dyeing studies of wool fabric

Environmental friendly products particularly natural dyes are going to be much popular around the globe due to their non-toxic and bio-degradable nature. The current study was planned to enhance the dyeability of walnut bark having juglone as a reddish-brown natural dye under ultrasonic radiation as an environment-friendly and green tool After conducting series of experiments, it has been found that wool (RW) and extract (RE) after ultrasonic treatment for 45 min, when dyed for 45 min at 55°C using an acidic bath of 3 pH has given good color strength on the wool fabric. To develop the new shades, sustainable and eco-label chemicals (Fe, Al, and tannic acid) and four bio-mordants such as Acacia bark, Turmeric, Henna, and Pomegranate were also applied at optimum conditions. It is studied that 3% of turmeric extract as pre-bio-mordant and 5% of Acacia extract as post-bio-mordant has given excellent color characteristics as compared to their synthetic. It is concluded that ultrasonic treatment being an eco-friendly tool has a great potential to improve the dyeability of natural reddish-brown dye from walnut bark and the inclusion of sustainable biosources as a color modifier has value-added the natural dyeing process with excellent color ratings.

Subcritical and supercritical water oxidation for dye decomposition

The total annual output of synthetic dyes exceeds 7 × 10⁵ tons. About 1,000 tons of non-biodegradable synthetic dyes are released every year into the natural streams and water sources from textile wastes. The release of these colored wastewater exerts negative impact on aquatic ecology and human beings because of the poisonous and carcinogenic repercussions of dyes involved in coloration production. Therefore, with a growing interest in the environment, efficient technologies need to be developed to eliminate dyes from local and industrial wastewater. Supercritical water oxidation as a promising wastewater treatment technology has many advantages, such as a rapid reaction and pollution-free products. However, due to corrosion, salt precipitation and operational problems, supercritical water oxidation process did not gain expected industrial development. These technical difficulties can be overcome by application of non-corrosive subcritical water as a reaction medium. This work summarizes the negative impacts of dyes and role of subcritical and supercritical water and their efficiencies in dye oxidation processes.

Diversity of Synthetic Dyes from Textile Industries, Discharge Impacts and Treatment Methods

Natural dyes have been used from ancient times for multiple purposes, most importantly in the field of textile dying. The increasing demand and excessive costs of natural dye extraction engendered the discovery of synthetic dyes from petrochemical compounds. Nowadays, they are dominating the textile market, with nearly 8 × 105 tons produced per year due to their wide range of color pigments and consistent coloration. Textile industries consume huge amounts of water in the dyeing processes, making it hard to treat the enormous quantities of this hazardous wastewater. Thus, they have harmful impacts when discharged in non-treated or partially treated forms in the environment (air, soil, plants and water), causing several human diseases. In the present work we focused on synthetic dyes. We started by studying their classification which depended on the nature of the manufactured fiber (cellulose, protein and synthetic fiber dyes). Then, we mentioned the characteristics of synthetic dyes, however, we focused more on their negative impacts on the ecosystem (soil, plants, water and air) and on humans. Lastly, we discussed the applied physical, chemical and biological strategies solely or in combination for textile dye wastewater treatments. Additionally, we described the newly established nanotechnology which achieves complete discharge decontamination.

A Brief History of Colour, the Environmental Impact of Synthetic Dyes and Removal by Using Laccases

The history of colour is fascinating from a social and artistic viewpoint because it shows the way; use; and importance acquired. The use of colours date back to the Stone Age (the first news of cave paintings); colour has contributed to the social and symbolic development of civilizations. Colour has been associated with hierarchy; power and leadership in some of them. The advent of synthetic dyes has revolutionized the colour industry; and due to their low cost; their use has spread to different industrial sectors. Although the percentage of coloured wastewater discharged by the textile; food; pharmaceutical; cosmetic; and paper industries; among other productive areas; are unknown; the toxic effect and ecological implications of this discharged into water bodies are harmful. This review briefly shows the social and artistic history surrounding the discovery and use of natural and synthetic dyes. We summarise the environmental impact caused by the discharge of untreated or poorly treated coloured wastewater to water bodies; which has led to physical; chemical and biological treatments to reduce the colour units so as important physicochemical parameters. We also focus on laccase utility (EC 1.10.3.2), for discolouration enzymatic treatment of coloured wastewater, before its discharge into water bodies. Laccases (p-diphenol: oxidoreductase dioxide) are multicopper oxidoreductase enzymes widely distributed in plants, insects, bacteria, and fungi. Fungal laccases have employed for wastewater colour removal due to their high redox potential. This review includes an analysis of the stability of laccases, the factors that influence production at high scales to achieve discolouration of high volumes of contaminated wastewater, the biotechnological impact of laccases, and the degradation routes that some dyes may follow when using the laccase for colour removal.

Textile dyes Maxilon blue 5G and Reactive blue 203 induce acute toxicity and DNA damage during embryonic development of Danio rerio

Common textile dyes used in various industrial sectors are organic compounds and considered for the aquatic environment as pollutants. The textile dye industry is one of the main sectors that have serious impacts on the environment due to a large amount of wastewater released into the ecosystem. Maxilon blue 5G (MB-5G) and Reactive Blue 203 (RB-203) are widely used textile dyes. However, their potential toxicity on living organisms remains to be elucidated. Here, we investigate the acute toxicity and genotoxicity of MB-5G and RB-203 dyes using the zebrafish embryos/larvae. Embryos treated with each dye for 96 h revealed LC₅₀ values of acute toxicity as 166.04 mg L^-1 and 278.32 mg L^-1 for MB-5G and RB 203, respectively. When exposed to MB-5G and RB-203 at different concentrations (1, 10, and 100 mg L^-1) for 96 h, the expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, significantly increased in brain tissues as compared to control. MB-5G and RB-203 resulted in common developmental abnormalities including tail malformation, microphthalmia, pericardial edema, curved body axis, and yolk sac/pericardial edemas. Moreover, at its highest dose (100 mg L^-1), RB-203 caused premature hatching after 48 h, while MG-5G did not. Our results collectively reveal that the textile dyes MB-5G and RB-203 cause genotoxicity and teratogenicity during embryonic and larval development of zebrafish. Thus, it is necessary to eliminate these compounds from wastewater or reduce their concentrations to safe levels before discharging the textile industry wastewater into the environment.

State of the art of post-consumer textile waste upcycling to reach the zero waste milestone

The textile industry is a large source of pollution due to the production of raw materials (natural and synthetic fibers), preparation and finishing processes, as well as due to textile waste, especially the post-consumer waste. This paper is an attempt to change the perception concerning such waste. In the context of circular economy, textile waste has to be conceived as a source for carbon and energy. A new attitude is compulsory due to the increase of post-consumer waste quantity since the volume of textile consumption has lately increased. Fast fashion cycle and cheaper textile products having a shorter lifetime led to an increase of the quantity of post-consumer textile waste. Demands for pollution reduction generated the concern to upcycle the textile waste in order to recover, at least partially, the materials as well as the energy consumed for their manufacture, reducing accordingly the carbon and water footprints of these products,. The scarcity of raw materials and of fossil fuels, the high environmental impact of the simple disposal of waste, imposed a new policy regarding the transformation of the linear economy which characterizes today's textile industry into a circular one, leading to a lower environmental impact. This involves the valorization of post-consumer waste by recycling or at least by a partial recovery of the materials and energy spent for the manufacture of these products. A good management of post-consumer textile waste is mandatory for attaining a zero waste target. Some good practices in the field are presented by this paper.

Removal of color from real textile dyeing effluent utilizing tannin immobilized jute fiber as biosorbent: optimization with response surface methodology

The present study explored an efficient technoeconomic method for treating intensely colored dyeing effluents from a commercial source. Firstly, the adsorption efficacy of jute fiber (JF) was enhanced through grafting with tannin, a natural polyphenol, via incorporation of active epoxy groups by epichlorohydrin onto fiber surface. The effect of different experimental parameters (e.g., initial pH, adsorbent dose, temperature, and contact time) on extent of color removal was evaluated performing batch studies. A full factorial central composite design (CCD) in response surface methodology (RSM) was applied to optimize the decolorization process for achieving maximum color removal (99.5%) at pH 4.9, adsorbent dose 11.8 g/L, temperature 30 °C, and time of contact 117.8 min. The isotherm and kinetic studies of the process revealed that Langmuir model and pseudo-second-order model provided best fit, yielding high correlation coefficients (R² > 0.997). Significant desorption (76%) of the spent adsorbent by 0.1 M NaOH solution suggested that this tannin-modified JF can find a prospective practical application as a novel, inexpensive, and potential bioadsorbent to treat the dyeing effluent.

Cleaner colorant extraction and environmentally wool dyeing using oak as eco-friendly mordant

Textile and dyeing are one of the most significant industries in many states. The employing of natural dyes in dyeing procedure is very important due to the environmental security of the area. To obtain a green, clean, and environmentally friendly dyeing of yarns, two natural dyes of madder and weld, which are native to Iran, were employed for dyeing yarns for carpet preparation. Due to the low affinity of natural dyes and maintaining the biocompatibility of the dyeing process, the oak was used as a new tannin rich mordant. The ultrasound-microwave-assisted method in water solution was used for extraction, and yield to the process was obtained about 27, 32, and 36% for madder, weld, and oak, respectively. The extractions were analyzed by UV-Visible and SEM techniques, and the ash, humidity, and density properties of these were investigated. The pre-mordanting method was employed for this study, and ferrous sulphate was used for compare of natural mordant performance. The washed, mordanted, and dyed yarns were investigated by analytical techniques, and the accuracy of these processes was confirmed. The fastness properties as well as the colorimetric characteristics of dyed yarns were assessed using related standards, and the dyed yarns have acceptable performance and could compete with metal mordant, colorimetrically.

Effects of Technical Textiles and Synthetic Nanofibers on Environmental Pollution

Textile manufacturing has been one of the highest polluting industrial sectors. It represents about one-fifth of worldwide industrial water pollution. It uses a huge number of chemicals, numerous of which are carcinogenic. The textile industry releases many harmful chemicals, such as heavy metals and formaldehyde, into water streams and soil, as well as toxic gases such as suspended particulate matter and sulphur dioxide to air. These hazardous wastes, may cause diseases and severe problems to human health such as respiratory and heart diseases. Pollution caused by the worldwide textile manufacturing units results in unimaginable harm, such as textile polymers, auxiliaries and dyes, to the environment. This review presents a systematic and comprehensive survey of all recently produced high-performance textiles; and will therefore assist a deeper understanding of technical textiles providing a bridge between manufacturer and end-user. Moreover, the achievements in advanced applications of textile material will be extensively studied. Many classes of technical textiles were proved in a variety of applications of different fields. The introductory material- and process-correlated identifications regarding raw materials and their transformation into yarns, fibers and fabrics followed by dyeing, printing, finishing of technical textiles and their further processing will be explored. Thus, the environmental impacts of technical textiles on soil, air and water are discussed.

Green textile production: a chemical minimization and substitution study in a woolen fabric production

This study aimed to decrease chemical costs and increase productivity and environmental performance by applying various practices for chemical minimization and substitution in an integrated textile mill producing woolen textile fabric. Detailed on-site process investigations and data collection studies were carried out in the mill. Process-based specific auxiliary chemical and dyestuff consumptions were calculated. Process and composite wastewater samples were collected at different periods and analyzed. The chemical loads of wastewaters were also calculated. The specific dyestuff and auxiliary chemical consumptions of the mill were compared with the data of a similar textile mill in the literature and the Integrated Pollution Prevention and Control (IPPC), Textile Best Available Techniques Reference (BREF) document. Thus, the chemical saving potential of the mill was evaluated. A detailed chemical inventory study was also carried out in the mill. The material safety data sheets (MSDSs) of 371 chemicals were examined in terms of biodegradation ratio, toxicity, and micropollutant content. As a result, 23 chemicals were proposed to be replaced with environmentally friendly substitutes. A total of 10 minimization and substitution practices were identified for the mill according to the investigation and analysis results. After the implementation of the suggested practices, reductions of 15-32 and 13-37% are estimated to be achieved in total chemical consumption and chemical oxygen demand (COD) load of wastewater, respectively. The potential payback periods of the suggested practices were calculated to range between 4 and 36 months. The employed methodology and the findings of this study may be useful for similar textile mills, stakeholders, and regulators. This study may also provide a road map to the textile industry for their sustainable and green production applications.

Structural equation modeling for three aspects of green business practices: a case study of Bangladeshi RMG's industry

Green business (GB) had often been regarded as a pervasive trend that underlies the operations and performance of businesses. By portrayal of three aspects view of the green business, this paper evaluates green business approaches within the Bangladeshi ready-made garments (RMG) sector and provides a structured framework for the factors affecting the utilization of green business approaches. This study further evaluates how the environmental, societal, and economic impact derived green business practices. The framework is experimentally tested by the partial least square approach to structural equation modeling (PLS-SEM) concentrated on survey responses quantifying the green business practices within 40 RMG organizations situated in Dhaka and Chittagong, Bangladesh. The findings demonstrate that there is a positive relationship between environmental, social, and economic aspects. More specifically, the PLS-SEM estimation demonstrates that the interaction between environmental and economic sustainability has a substantial proportion of values towards profiling GB practice. Meanwhile, there is a vast gap for profiling the performances of environmental and economic aspects through social aspects within the RMG sectors of Bangladesh. Also, there is a significant difference between the predicted and factual green business adoption tendencies and views among different industrial enterprises, especially for waste management and water pollution based on the findings of the SEM-PLS model. Throughout the context of the rapid growth of socioeconomic development and new technological advancement, social level performance possess comparably weak influences of GB strategy on the within Bangladeshi RMG sectors. In the meantime, as the stricter law has a vital impact on the firm's strategies for becoming more environmentally friendly practices, it instituted as an essential variable for quantifying social sustainability. Moreover, the study recommends some suggestions emphasizing the part of the identified model in the context of encouraging business organizations to indulge in environment-oriented socio-economy actions and thus change the emphasis of potential GB study directions.

Comparison between Allura Red dye discoloration by activated carbon and azo bacteria strain

Azo dyes are extensively used in different industries areas, such as Allura Red (R-40). Previous studies have proven its carcinogenic and mutagenic properties. For the removal of this type of emerging pollutant from effluents, tertiary treatment techniques such as activated charcoal are used. Alternatively, the use of bacteria is preferred because of its quick discoloration processes. The aim of the present investigation is to compare the efficiency removal of R-40 from aqueous media by a physicochemical process and a biological one. The sorption kinetics of 10 ppm of R-40 was carried out with the use of activated charcoal based on walnut shells in water. Moreover, Pseudomonas aeruginosa and Bacillus subtilis stains were used separately to decolorize nutrient broth media supplemented with 50 ppm of R-40. The activated carbon was capable to remove 99.87% of R-40 at 264 h, while the bacterial strains decolorized 92.13% (P. aeruginosa) and 88.21% (B. subtilis), respectively, under microaerophilic conditions after 168 h. Therefore, both process strategies, physicochemical and biological rapprochements, were able to remove the dye from aqueous media. R-40 was not cytotoxic to used strains, besides gram-positive either negative bacteria could be applied to turn over this azo dye in short term. Combination of both approaches may be implemented in tandem architecture.

Synthesis and Antimicrobial Evaluation of Some Novel Pyrimidine, Pyrazole, Chromene and Tetrahydrobenzo[b]thiophene Derivatives Bearing Pyrimidinthione Moiety

AIM AND OBJECTIVE

A novel collection of fused pyrimidine, pyridine, pyrazole, chromene and thiophene derivatives 2-30 have been newly synthesized by using the 1a, b as starting material. Fused pyrane exhibits a range of pharmacological activity such as cancer agents [1], antimicrobial [2-4], antioxidant [5], antiproliferative [6], cytotoxic activity [7], anticipated antitumor [8], antiparkinsonian [9] and anti-inflammatory [10]. Moreover, pyrane derivatives are well known for bacterial biofilm disruptor [11], anticonvulsant [12] and inhibitors of mycobacterium bovis [13].

MATERIALS AND METHODS

All melting points were measured using the Akofler Block instrument and are uncorrected. IR spectra (KBr) were recorded on a FTIR 5300 spectrometer (υ, cm-1). The 1H-NMR spectra were recorded on a Varian Gemini spectrometer. The 1H-NMR spectra were run at 300, 400 MHz and 13C-NMR spectra were run at 100 MHz in DMSO-d6, CDCl3 as solvents. The chemical shifts are expressed in parts per million (ppm) by using tetramethylsilane (TMS) as an internal reference, 1000 EX mass spectrometer at 70 eV. The purity of synthesized compounds was checked by thin-layer chromatography (TLC) (aluminum sheets) using nhexane, EtOAc (9:1, V/V, 7:3 V/V) eluent. Elemental analyses were carried out by the Microanalytical Research Center, Faculty of Science, and Microanalytical Unit, Faculty of Pharmacy, Cairo University, Egypt.

RESULTS AND DISCUSSION

A novel series of azoles and azines were designed and prepared via the reaction of 7-amino- 5-(4-chlorophenyl)-4-phenyl-2-thioxo-2,5-dihydro-1H-pyrano- [2,3-d]pyrimidine-6-carbonitrile 1a and 7-amino-4,5- diphenyl-2-thioxo-2,5-dihydro-1H-pyrano[2,3-d]-pyrimidine-6-carbonitrile 1b with some electrophilic and nucleophilic reagents. The structures of target compounds were confirmed by elemental analyses and spectral data. The novel synthesized compounds showed good antimicrobial activity against the previously mentioned microorganisms.

CONCLUSION

In conclusion, compounds 1a, 1b underwent ready cyclization to give fused heterocyclic compounds through reaction with different reagents and under different conditions and subjected to antimicrobial screening.

Congo Red Decolorization Using Textile Filters and Laccase-Based Nanocomposites in Continuous Flow Bioreactors

Removal of azo and diazo dye content from textile industry wastewaters is crucial due to their environmental impact. Here, we report on the use of the fungal laccase from Pycnoporus sanguineus CS43 immobilized on silica nanoparticles and entrapped in textile-based filters for the degradation of Congo Red. Laccase immobilization and synthesis of the nanocomposites were carried out by two different methods, one in the presence of acetone and the second using water as solvent. This led to a change in the hydrophobicity of the obtained biofilters. Successful preparation of the nanocomposites was confirmed via FTIR spectroscopy. Changes in the secondary structure of the enzyme were inspected through the second derivative of the FTIR spectra. Six different types of filter were fabricated and tested in a continuous flow bioreactor in terms of their decolorization capabilities of Congo Red. The results indicate removal efficiencies that approached 40% for enzymes immobilized on the more hydrophobic supports. Backscattered electron (BSE) images of the different filters were obtained before and after the decolorization process. Percentage of decolorization and activity loss were determined as a function of time until a plateau in decolorization activity was reached. Experimental data was used to recreate the decolorization process in COMSOL Multiphysics® (Stockholm, Sweden). These simulations were used to determine the proper combination of parameters to maximize decolorization. Our findings suggest that the treatment of textile-based filters with immobilized laccase in conjunction with hydrophobic nanocomposites provides a suitable avenue to achieve more efficient laccase dye decolorization (39%) than that obtained with similar filters treated only with free laccase (8%). Filters treated with silica-based nanocomposites and immobilized laccases showed an increase in their decolorization capability, probably due to changes in their wetting phenomena.

Morphology engineering of ZnO nanorod arrays to hierarchical nanoflowers for enhanced photocatalytic activity and antibacterial action against Escherichia coli

A facile, efficient hydrothermal synthesis of ZnO nanoflowers followed by post-synthetic annealing and their photocatalytic and antibacterial properties are reported.